Cellular telephones, personal communication service equipment, personal data assistants, and other wireless devices have gained wide scale acceptance in both commercial and personal markets. When using these devices, the quality and clarity of the wireless communications depends greatly upon having adequate signal strength relative to any local interference. Signal strength is a primary factor determining the quality of the link between the mobile unit and a local base station. The versatility of these devices however, lies in their ability to move throughout the working area unimpeded by wires, docking stations, modem connections and the like. This flexibility is founded in the ability of base stations, which are located throughout the working area, to seamlessly transfer the mobile link amongst themselves.
Mobile telephones and other wireless devices are dependent on their link to fixed devices established in a network. This link is accomplished by providing access points, or base station units, that can hand off the connection of mobile devices without an interruption of service. Many problems exist with such wireless networks. Networks often have limited capacity and generally provide only low bandwidth or narrow band access. Even more troubling, the service is frequently unreliable and restricted in areas such as buildings, convention centers, subways, airports, train stations and many commercial enterprises. These restrictions can be due to the inherent physical characteristics of the floors and walls in the building, the building material used to construct the building, or the electromagnetic spectrum associated with operations on-going at those locations. One proposed solution to these limitations and problems has been the development of personal communications networks. Personal communication networks typically have greater bandwidth and possess a higher user capacity, but still face the same problems associated with the physical and operational characteristics of commerce, i.e. buildings and the working environment.
As technology evolved to solve these problems, many businesses installed wireless local area network base stations within their working environment. Current technology requires these base stations, which form a network, to have coverage that overlaps such that it eliminates or minimizes the presence of zones where the coverage capability is so poor that communication is not possible, i.e. dead zones. Such overlaps are a prerequisite for base station-to-base station handoffs without communications on a mobile station being dropped. To accomplish this, each base station is typically given knowledge of base stations to which they can hand off a mobile unit. Typically, a base station controller communicates with base stations and coordinates a hand off of a mobile device. To do so each base station must communicate to the controller the quality of the links between itself and its neighboring base stations. This process is complex and requires significant resources to manage the high volume of handoffs created by the ever increasing number of mobile units. Furthermore, it is difficult to keep on top of the changing local environment, which can affect the coverage and links between base stations.
When installing wireless local area network base stations within a corporate environment, it is necessary to properly locate each base station such that sufficient wireless coverage exists throughout the working area. Typically, this involves analyzing variables such as the corporate floor plan, fixed wall construction, cubicle location and material, as well as what is being done at the location in order to estimate optimal base station placement. Once completed, a technician, generally using portable wireless test equipment, can verify each stations placement and coverage. There are software-based (e.g. AutoCAD) floor plans that can be used for automated analysis, but often the current office floor plan is either not drawn in the software, does not exist, or is inaccurate. Additionally, such programs provide no feedback regarding actual operating conditions. Furthermore, this process, if accomplished at all, typically occurs only during the installation process, and is not repeated unless errors are reported by users that require a service visit, reinstallation of the current base stations or installation of additional base stations. While methods exist to locate and evaluate the link between wireless base stations and mobile units, these devices offer little to no feedback on the links between individual base stations. Examples of such systems can be found in U.S. Pat. Nos. 6,035,183, 5,960,341, 5,602,903, 5,508,707, and 5,675,344 as well as European Patent Application No. EP 1,051,049 A2 and Great Britain Patent No. 2,275,848. These references describe displays that are located on a mobile unit or interface with a central controller to locate a mobile unit but fail to convey the quality of the links between participating base stations.
In each of the forgoing cases, local area network managers cannot on a day-to-day basis monitor the signal strength and quality of links between one base station and its neighbors. As companies and enterprises grow, change, or are replaced, the environment in which they operate changes. Changes in the working environment undoubtedly alter the coverage capability of each base station; yet without repeating the installation process the actual capability is unknown. As a result, users cannot make informed decisions on the reliability of the coverage areas in which they operate mobile units. Lacking such reliability, user confidence regarding mobile devices erodes, thereby defeating the very purpose for such units and decreasing workplace productivity.
In the drawings, the same reference numbers identify identical or substantially similar elements or acts. To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the Figure number in which that element is first introduced (e.g., element 404 is first introduced and discussed with respect to FIG. 4).
Figure numbers followed by the letters “A,” “B,” “C,” etc. indicate that two or more Figures represent alternative embodiments or methods under aspects of the invention. The headings provided herein are for convenience only and do not necessarily affect the scope or meaning of the claimed invention.